The biotransformation of three groups of organic chemicals, widely used in chemical industry and known to constitute industrial health hazards, are to be studied. These are: 1) The six polychloroethanes; 2) the allyl and acrylyl compounds and their derivatives; and 3) the solvent dioxane. Emphasis will be placed upon the identification of metabolites and establishment of metabolic pathways for these compounds in vitro, and upon description of the characteristics of the enzymic reactions involved in the pathways. Preparations of microsomes and of other subcellular fractions of liver and of other organs of rats, rabbits, and mice will be used. Metabolites will be separated and quantified by gas-liquid, liquid-liquid, thin-layer, and paper chromatographic techniques.